1. Field of the Invention
The present invention relates to a mobile terminal, and more particularly to a sliding module for a mobile terminal which connects a sub-housing to a main housing to enable the sub-housing to be slidable upwardly and downwardly on the main housing in a longitudinal direction of the mobile terminal.
2. Description of the Related Art
Generally, mobile terminals are classified as either a bar type, a flip type, or a folder type terminal according to their shape. A bar-type mobile terminal has a single housing provided with a communication circuit and data input/output means altogether. A flip-type mobile terminal is an improvement of a bar-type terminal having a flip cover. A folder-type mobile terminal has a pair of housings provided with a communication circuit and data input/output means. Currently, the folder type terminal dominates the mobile phone market due to its lighter and smaller design.
Recently, new designs such as a slide type terminal and a swing type terminal have also been introduced to meet the diverse needs and tastes of users. The slide type terminal or the swing type terminal has a pair of facing housings, one of which is slidable or rotatable on the other. Also, mobile terminals capable of composite open/close operations by combining the folder type with the swing type have been introduced.
Among the above designs, slide-type phones are gaining popularity with their efficiency, because they do not require distinct opening and closing movements for use.
A slide-type terminal has a pair of housings, one of which slides on the other facing housing in a longitudinal direction to partially open or close the other housing. Specifically, a keypad with number/character keys or a display window is opened or closed according to the slidable movement.
A user can directly move one housing upward or downward on the other housing within the limits of slidable movement. Alternatively, the user can use a spring or a driving motor to make one housing automatically or semi-automatically slide on the other housing.
U.S. Patent Application No. 379,551 (filed Mar. 6, 2003), commonly assigned to the assignee of the present application, discloses a sliding module for semi-automatically opening or closing a slide-type mobile terminal. The disclosed sliding module uses the elasticity of a spring to open or close the terminal. Within certain limits, the sliding module generates an elastic force that makes one housing slide on the other housing in a direction to cover the keypad provided on the other housing. Beyond the limits, the sliding module generates an elastic force to move one housing in an opposite direction to open the keypad on the other housing.
Although a variety of designs have been developed for mobile terminals, they do not completely satisfy the diverse tastes of users. Recently introduced designs merely provide improvements in open/close operations, without diversifying functions.